1. Field of the Invention
The present invention relates to start controlling of a plurality of control units that can start themselves respectively and independently of each other.
2. Description of the Related Art
Some electronic equipment, such as an image forming apparatus, includes a plurality of functional units. In such electronic equipment, parts that correspond to one function are assembled into a module. Moreover, a control means is provided corresponding to each function to individually control the function. Such a control unit includes a control means (CPUs and the like) whereby the control unit can operate respectively and independently of each other. The control means control starting and stopping of their respective control units, independently of each other.
A start method called “hibernation” is widely used to reduce a start time of electronic equipment. For example, Japanese Patent Application Laid-open No. 2002-207537 discloses a conventional technology in which a computer system includes a system start selecting unit for selecting, at the time of a start-up of the computer system, either of a first system-start mode in which a hibernation function is invalidated when the computer system is started from a stop state of the computer system, and a second system-start mode in which the hibernation function is validated when the computer system is started from the stop state of the computer system, and when the second system-start mode is selected by the system start selecting unit, the hibernation function is validated and then the computer system is started.
However, when the hibernation is used in the electronic equipment including the plurality of control unit, and the start methods of all of the control units are not matched, a mismatch of data sent between the control units can occur. For example, when firmware is updated in one of the control units, the control unit is required to be started with a normal start mode to reflect the update and update information sent to/from another of the control unit. In this case, when another of the control units included in the same electronic equipment is started with the hibernation, the control unit can fail to operate normally at a restart of the control unit.
Because Japanese Patent Application Laid-open No. 2002-207537 does not describe about any application to an electronic equipment including a plurality of control units that start themselves respectively and independently of each other, it is impossible to control the start methods of the control units, individually. A user has to make a choice between the start method with the hibernation and the normal start method, consciously. Thus, the operation is inconvenient for the user, and it is difficult to always select the correct start method depending on states of the control unit.